Improve compiler warning to include the offending file when emitting error in RISCVTargetLowering

[hiraditya]

the warning generated from:

llvm-project/llvm/lib/Target/RISCV/RISCVISelLowering.cpp

Lines 94 to 98 in 4ed543d

	"target-abi)\n";
	ABI = Subtarget.is64Bit() ? RISCVABI::ABI_LP64 : RISCVABI::ABI_ILP32;
	} else if ((ABI == RISCVABI::ABI_ILP32D || ABI == RISCVABI::ABI_LP64D) &&
	!Subtarget.hasStdExtD()) {
	errs() << "Hard-float 'd' ABI can't be used for a target that "

doesn't include the module name, which makes it hard to find which file error was coming from?

It might be okay with non-lto + non-parallel builds but it becomes hard to debug the problem otherwise.

Context: #69780 (comment)

[llvmbot]

@llvm/issue-subscribers-backend-risc-v

Author: AdityaK (hiraditya)

the warning generated from:

llvm-project/llvm/lib/Target/RISCV/RISCVISelLowering.cpp

Lines 94 to 98 in 4ed543d

	"target-abi)\n";
	ABI = Subtarget.is64Bit() ? RISCVABI::ABI_LP64 : RISCVABI::ABI_ILP32;
	} else if ((ABI == RISCVABI::ABI_ILP32D || ABI == RISCVABI::ABI_LP64D) &&
	!Subtarget.hasStdExtD()) {
	errs() << "Hard-float 'd' ABI can't be used for a target that "

doesn't include the module name, which makes it hard to find which file error was coming from?

It might be okay with non-lto + non-parallel builds but it becomes hard to debug the problem otherwise.

Context: #69780 (comment)

[topperc]

By the time we get here there should only be one Module. Do you want the Function name?

Given where the error is, it's impossible to get the function name. We would need to do it in getSubtargetImpl in RISCVTargetMachine I think.

[hiraditya]

The function name is even better. Backtrace from within gdb tells me that Function is available only two levels up.